Pharyngitis accounts for 6.4% of office visits and 10% of total antibiotic prescriptions in the U.S. Although viruses are the most common cause of pharyngitis, approximately 15-36% of children will have a bacterial cause such as Group A Streptococcus (GAS). Ideally, physicians would treat only bacterial causes with antibiotics. However, studies have found that 70-80% of children who are seen for pharyngitis will receive an antibiotic prescription, suggesting that physicians may be excessively recommending antibiotic use. Such overuse of antibiotics has led to growing concerns over the development of antibiotic resistance in the community. GAS vaccine trials are underway in the U.S. and Canada. If the vaccine proves efficacious, it will not only have the potential to prevent GAS disease such as pharyngitis, invasive disease, and rheumatic fever, but it may also reduce unnecessary antibiotic prescribing and rates of resistance in the community. Decisions will need to be made about reasonable and cost-effective vaccine use once it becomes available. The goal of this proposal is to enhance our understanding of how to incorporate patient preferences and advanced modeling methods in evaluating the cost-effectiveness of interventions against infections. The candidate will address 4 specific aims: (1) To determine the societal costs and health state preferences for GAS infection such as pharyngitis; (2) To create a decision-analytic model to estimate the costs and health outcomes of selective vaccination strategies to prevent invasive GAS disease; (3) To determine the cost-effectiveness of universal vaccination strategies for infants and/or children through mathematical modeling; and (4) To evaluate the costs and outcomes of current management strategies for pharyngitis and model the potential downstream impact of a GAS vaccine. The overall goal of this K08 Award is to contribute to the professional, academic, and research development of the candidate. Her commitment to improving the health outcomes of children combined with her expertise in pediatric infectious diseases provides a strong foundation for this proposal. In addition to pursuing formal training at Harvard School of Public Health and the Kennedy School of Government, she will receive guidance and support from a team of accomplished mentors and advisors. During her K Award, she hopes to establish herself as a multidisciplinary researcher in the fields of decision sciences, infectious disease modeling, and health policy. [unreadable] [unreadable]